I have been using a file manager called Novatix ExplorerPlus, which has been out of business for some time so their software is no longer supported. ExplorerPlus has one synchronization feature called "Match folders", which I wish FreeCommander had.

Below is description of the Match Folders feature in ExplorerPlus:

"Matching Folders
Do you have two folders that absolutely have to be identical? Easy Synchronizer can duplicate the contents of one folder in another folder. This action will copy any files in the source folder to the target folder, whether it’s newer or older. It will also delete any files on the target folder that are not in the source folder.

CAUTION: The Match operation attempts to make the target identical to the source. That means newer files on the target can be overwritten by older files from the source, and that files on the target may be deleted."
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NOTE:
I find the Match Folders feature essential for me to manage my many tens of thousands of photos stored across a series of hard drives.
This includes Adobe Lightroom side car files that contain information regarding non-destruction edits done in Lightroom.

Half of my hard drives are designated prime storage devices and the other half as backup storage devices.
Using the "Match Folder" feature, I can ensure changes to my prime storage can be made to my backup storage easily.
PS: I also have a RAID 5 NAS for storage, but it is now full, so I have expanded my storage capability using separate external drives which is a cheaper (although less robust) option at the moment.

Matching Folders
Do you have two folders that absolutely have to be identical? Easy Synchronizer can duplicate the contents of one folder in another folder. This action will copy any files in the source folder to the target folder, whether it’s newer or older. It will also delete any files on the target folder that are not in the source folder.

I hate all sonds on my systems, so I removed many of them and I changed with quite sound the rest of them, I like hear music, I'm happy that in Win 8 is possible to have a specific volume for sounds system.
Anyway I think this feature could be very useful